Chap 1- Stats intro Flashcards
Statistics
- ) mathematical procedure –> organizing, summarizing and interpreting information
- ) numerical value that describes sample
- -> derived from individuals in sample
Population
set of all individuals of interest in a study
Sample
set of individuals selected from pop
-intended to represent the pop in research study
Variable
characteristic or condition that varies
Data
(pural) measurement or observation
Data set
collection of measurement or observations
Datum
(singular) single measurement or observation –> score or raw score
Parameter
- value/numerical value that describes population
- from measurements of individuals in the population
Descriptive statistic
statistical procedure –> summarize, organize and simplify data
Inferential statistics
-technique –> study samples and make generalization about the pop from which they are selected
Sampling error
naturally occurring
- discrepancy/error between populations parameter and samples statistics
Correlation method
Two dif. Variables are observed to determine whether there is a relationship between
experimental method
one variable is manipulated while the variable is observed and measured.
- establish cause and effect relationship between the two variables.
- experiment attempts to control all of the other variables to prevent them from influencing the results
percentile
in Ordered series
- it’s the POINT @ or BELOW, where half the scores lie
independent variable
- variables manipulated the experimenter, independently of all other variables
- hypothesized to be causal
subjective variable
- Intrinsic characteristic research subject (height, IQ, ect)
- researcher is UNABLE to manipulate
- hypothesis to be causal
dependent variable
behavioral variable measured to determine :
effect of independent variable
possible effect of the subject variable
control condition
- DO NOT receive experimental treatment
- receive no treatment or a placebo treatment
- provides a baseline for comparison with the experimental condition
experimental condition
to receive the experimental treatment
quasi independent variable
in a non experimental study
the “independent variable” that is used to create the different groups of scores
constructs
internal attributions are characteristics
-Cannot be directly observed but are useful for describing and explaining Behavior
operational definition
identifies a measurement procedure for a set of operations
- for measuring an external behavior and uses the resulting measurements as a definition and hypothetical construct
1) describe a set of operations for measuring a construct
2) defines the construction terms of the resulting measurements
discrete variable
consists of separate, indivisible categories.
-no values can exist between two neighboring categories
continuous variable
there are an infinite number of possible values that fall between any two observed values
-a continuous variable is divisible into a infinite number of fractional parts.
real limits
boundaries of intervals for scores that are represented on a continuous number line
- real limit separating two adjacent scores is located exactly halfway between the scores
A) upper real limit= at the top of the interval
B) lower real limit= at the bottom of the interval
nominal scale
consists of a set of categories that have different names
- measurements on a nominal scale label and categorize observations
- measurements on a normal nominal scale DO NOT make any quantitative distinctions between observations
(use bar graphs)
ordinal scale
a set of categories that are organized in an ordered sequence
- measurements on an ordinal scale rank observations in terms of size or magnitude
(use bar graphs)
interval scale
order categories that are all intervals of exactly the same size
- equal differences between numbers on scale reflect equal differences in magnitude
- 0 on the interval scale is arbitrary and does not indicate a zero amount of the variable being measured
(use histogram graphs)
a ratio scale
interval scale with the additional features of an absolute zero point
- ratios of numbers to reflect ratios magnitude
(use histogram graphs)
Box and Whiskers plot
- skewed : right = positive, left= negative
a. ) whiskers differ in length
b. ) (median minus the first quartile does not equal the 3rd quartile minus the median
c. ) same thing for the minium score and max scores interactions with the median
deviation score
- number: the actual distance form the ,mean in unites measured
- sign: tells us the direction from the mean
- -> problem = unit sign fucks with statistics therefore…
a. ) use ‘average deviation’ = mean of |dev. score| ( doesn’t reflect population
b) avg of squared dev. –> variance
